Running vacuum cosmological models: linear scalar perturbations

Autor(es)

Perico, E. L. D. ; Tamayo, D. A.

• Tipo de documento: Artigo Científico
• Fonte: Journal of Cosmology and Astroparticle Physics; v. N/A, n. 8, p. 32-pg., 2017-08-01.

Resumo

In cosmology, phenomenologically motivated expressions for running vacuum are commonly parameterized as linear functions typically denoted by Lambda (H-2) or Lambda (R). Such models assume an equation of state for the vacuum given by (P) over bar Lambda =- (rho) over bar Lambda relating its background pressure (P) over bar Lambda with its mean energy density (rho) over bar Lambda equivalent to Lambda/8 pi G. This equation of state suggests that the vacuum dynamics is due to an interaction with the matter content of the universe. Most of the approaches studying the observational impact of these models only consider the interaction between the vacuum and the transient dominant matter component of the universe. We extend such models by assuming that the running vacuum is the sum of independent contributions, namely (rho) over bar Lambda = Sigma(i) (rho) over bar Lambda i.Each Lambda i vacuum component is associated and interacting with one of the i matter components in both the background and perturbation levels. We derive the evolution equations for the linear scalar vacuum and matter perturbations in those two scenarios, and identify the running vacuum imprints on the cosmic microwave background anisotropies as well as on the matter power spectrum. In the Lambda(H-2) scenario the vacuum is coupled with every matter component, whereas the Lambda(R) description only leads to a coupling between vacuum and non-relativistic matter, producing different effects on the matter power spectrum. (AU)

• Processo FAPESP: 15/01721-9 - Cosmologia de Voids e Halos em Gravidade Modificada
• Beneficiário: Eder Leonardo Duarte Perico
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 09/54006-4 - Um cluster de computadores para o Departamento de Astronomia do IAG-USP e para o Núcleo de Astrofísica da UNICSUL
• Beneficiário: Elisabete Maria de Gouveia Dal Pino
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários